The invention relates to a mobile sweeper comprising a housing, in which a sweeping roller driven by an electric motor is mounted for rotation, and a sweepings container for receiving sweepings, wherein there are mounted on the housing adjacent to the sweeping roller two front supporting wheels and at a distance from these at least one rear supporting wheel, each for rotation about an axis of rotation.
Such sweepers are known, for example, from EP 1 199 971 B1. They can be moved along a surface to be cleaned, and sweepings can be picked up from the surface to be cleaned by the sweeping roller and transferred to the sweepings container.
Such sweepers have proven to be effective for cleaning inside surfaces of buildings. As a rule, good cleaning results are obtained on even surfaces. However, surfaces outside buildings can often only be cleaned insufficiently with such sweepers. This is due to the unevennesses which often occur. These not only make moving the sweepers difficult. There is also the risk that the sweeping roller will be blocked by unevennesses or the sweeper will accidentally tilt about an axis aligned transversely to the main direction of movement.
The object of the present invention is to so develop a sweeper of the kind mentioned at the outset that also when surface unevennesses occur there is no risk of the sweeping roller being blocked or of the sweeper tilting.